<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2017, British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package	CodeIgniter
 * @author	EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
 * @copyright	Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/)
 * @license	http://opensource.org/licenses/MIT	MIT License
 * @link	https://codeigniter.com
 * @since	Version 3.0.0
 * @filesource
 */
defined('BASEPATH') or exit('No direct script access allowed');

/**
 * PDO CUBRID Database Adapter Class
 *
 * Note: _DB is an extender class that the app controller
 * creates dynamically based on whether the query builder
 * class is being used or not.
 *
 * @package CodeIgniter
 * @subpackage Drivers
 * @category Database
 * @author EllisLab Dev Team
 * @link https://codeigniter.com/user_guide/database/
 */
class CI_DB_pdo_cubrid_driver extends CI_DB_pdo_driver
{

    /**
     * Sub-driver
     *
     * @var string
     */
    public $subdriver = 'cubrid';

    /**
     * Identifier escape character
     *
     * @var string
     */
    protected $_escape_char = '`';

    /**
     * ORDER BY random keyword
     *
     * @var array
     */
    protected $_random_keyword = array(
        'RANDOM()',
        'RANDOM(%d)'
    );
    
    // --------------------------------------------------------------------
    
    /**
     * Class constructor
     *
     * Builds the DSN if not already set.
     *
     * @param array $params            
     * @return void
     */
    public function __construct($params)
    {
        parent::__construct($params);
        
        if (empty($this->dsn)) {
            $this->dsn = 'cubrid:host=' . (empty($this->hostname) ? '127.0.0.1' : $this->hostname);
            
            empty($this->port) or $this->dsn .= ';port=' . $this->port;
            empty($this->database) or $this->dsn .= ';dbname=' . $this->database;
            empty($this->char_set) or $this->dsn .= ';charset=' . $this->char_set;
        }
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Show table query
     *
     * Generates a platform-specific query string so that the table names can be fetched
     *
     * @param bool $prefix_limit            
     * @return string
     */
    protected function _list_tables($prefix_limit = FALSE)
    {
        $sql = 'SHOW TABLES';
        
        if ($prefix_limit === TRUE && $this->dbprefix !== '') {
            return $sql . " LIKE '" . $this->escape_like_str($this->dbprefix) . "%'";
        }
        
        return $sql;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Show column query
     *
     * Generates a platform-specific query string so that the column names can be fetched
     *
     * @param string $table            
     * @return string
     */
    protected function _list_columns($table = '')
    {
        return 'SHOW COLUMNS FROM ' . $this->protect_identifiers($table, TRUE, NULL, FALSE);
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Returns an object with field data
     *
     * @param string $table            
     * @return array
     */
    public function field_data($table)
    {
        if (($query = $this->query('SHOW COLUMNS FROM ' . $this->protect_identifiers($table, TRUE, NULL, FALSE))) === FALSE) {
            return FALSE;
        }
        $query = $query->result_object();
        
        $retval = array();
        for ($i = 0, $c = count($query); $i < $c; $i ++) {
            $retval[$i] = new stdClass();
            $retval[$i]->name = $query[$i]->Field;
            
            sscanf($query[$i]->Type, '%[a-z](%d)', $retval[$i]->type, $retval[$i]->max_length);
            
            $retval[$i]->default = $query[$i]->Default;
            $retval[$i]->primary_key = (int) ($query[$i]->Key === 'PRI');
        }
        
        return $retval;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * Truncate statement
     *
     * Generates a platform-specific truncate string from the supplied data
     *
     * If the database does not support the TRUNCATE statement,
     * then this method maps to 'DELETE FROM table'
     *
     * @param string $table            
     * @return string
     */
    protected function _truncate($table)
    {
        return 'TRUNCATE ' . $table;
    }
    
    // --------------------------------------------------------------------
    
    /**
     * FROM tables
     *
     * Groups tables in FROM clauses if needed, so there is no confusion
     * about operator precedence.
     *
     * @return string
     */
    protected function _from_tables()
    {
        if (! empty($this->qb_join) && count($this->qb_from) > 1) {
            return '(' . implode(', ', $this->qb_from) . ')';
        }
        
        return implode(', ', $this->qb_from);
    }
}
